Consider the following data drawn from two independent normally distributed populations:

Assume the population variances are 98.2 and 87.4 for groups 1 and 2 respectively. What is the 95% confidence interval for the difference in population means (₁ - ₂)?

group 1, group 2

mean 25.7 30.6

sample size 20 25

Select one:

None of these are correct

(-9.67, -0.13)

(-10.58, 0.78)

(-12.37, 2.57)

(-7.85, 0.85)